Air pump and gauge



May 15, 1923. 1,455,

c. MILLARD AIR PUMP AND GAUGE Filed Oct. 11 1921 2 Sheets-Sheet l May 15, 1923. 1,455,646

- C. MILLARD AIR PUMP AND GAUGE Filed Oct. 11, 1921 -2 Sheets-Sheet 2 INVEN TOR.

C Millarzi 1' TTORNEY.

Patented May 15, 1323..

barren s insane AIR PUMP AND GAUGE.

Application filed October 11, 1921. Serial No. 506,961.

To. all whom it may concern:

Be it known that I, CLARENCE liirLLAnD, a citizen'of the United States, residing at Arkansas City, in the county of Cowley and State of Kansas, have invented certain new and useful Improvements in Air Pumps and Gauges;'and l dov hereby declare the following to be a full,.clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

The invention relates to an air pump for inflating pneumatic tires and like devices containing air under pressure.

The principal object of the invention is to prevent over inflation of the tire or like part since the pump embodies a vent which is controlled by a valve operable by the air pressure whereby wvhen the predetermined pressure has been reached any excess resulting from the continued operation of the pump escapes.

()ther objects and advantages will be apparent and suggest themselves as the nature of the invention is understood.

vVhile the drawings illustrate an embodiment of the invention it is to be understood that in adapting the same to meet different conditions and requirements, various changes in the form, proportion and minor details of construction may be resorted to without departing from the nature of the invention.

Referring to the accompanying drawings forming a part of the specification,

Figure 1 is an elevation of an air pump embodying the invention.

Figure 2 is a vertical central longitudinal section thereof, an intermediate portion of the pump cylinder being broken away,

Figure3 is a transverse section on the line 3-3 of Figure 2, and

Figure 4 is a sectional detail of the connection between the air tube and the tire valve.

Corresponding and like parts are referred to in the following description and designated in the several views of the drawings by like reference characters.

The pump embodies a cylinder 1 and a piston 2 operable therein. The cylinder 1 is provided at its lower end with a base 3 whereby to form a support for the pump and enables the latter to be held by engagement of the feet with the base when the pump is in operation. A transverse partition 4 subdivides the cylinder into upper and lower chambers 5 and 6 respectively. The chamber 5 constitutes the working barrel of the pump and the chamber 6 receives the air pressure and is in communication with the tire or other part to be inflated by means of an air tube 7 which is provided with a coupling 8 to be attached to the tire valve 9 and of such construction as to hold the valve thereof open whereby the air chamber 6 of the pump has uninterrupted communication with the tire or like part so that the pressure in each is alike. The cylinder 1 is preferably of sectional formation and the partition 4: is clamped between the sections in a manner to insure a tight joint and thereby prevent escape of pressure. A. valve passage 10 establishes communication between the chambers 5 and 6, a passage 11 provides escape for excessive pressure. Both passages 10 and 11 are formed in the partition 4. The vent passage 11 establishes communication between the chamber 6 and the at- -mosphere. An upwardly movable valve 12 closes the vent passage 11 and is carried by pose a slide 15 is mounted in the base 3 and is movable therein to engage the spring 14: at any point in its length whereby the same is stifiened and its effective tension varied. The slide 15' is adjustable by means of a stem 16 which extends through a slot 17 formed in the base 3. A nut 18 mounted upon the projecting threaded end of the stem 16 provides convenient means for securing the slide 15 in the required adjusted position. Graduations 19 are provided along the base 3 adjacent the slot 17 and enable the slide 15 to be set to any determinate point according to the required pressure to which the tire or like part is to be inflated. The base 3 is preferably of sectional formation to admit of ready assemblage of the parts. The device is essentially a hand operated pump and in practice is manipulated in substantially the same manner as the ordinary or likevpart being inflated.

automobile foot pump. When it is required to inflate a tire the air tube 7 of the pump is coupled to the air valve 9 thereby establishing uninterrupted communication be .Onthe upstroke of the piston 2 the valve in the passage 10 closes thereby preventing re turn of air from the chamber 6 to the chamber 1. his operation is continued until the predetermined pressure has been reached and is the same in the-chamber 6 and the tire Any excessive pressureefiects unseating-of the valve 12 and an opening, of the vent passage 11 whereby the excess escapes. The uns'eating of the valve 12 is effected b 'the'air Jressure in the chamber 6 acting upon a diaphragm 20 or like part connected with the valve stem 13. When the air pressure on the diaphragm 20 or likepart exceeds the pressure exerted by, the spring 14 to hold the valve 12 seated,

said valve moves and uncovers the vent pas Jsagell, whereby an escape for. the excess of pressure is provided.

The coupling at the end of the tube! comprises .a nipple 21 which encloses an. ex-

pansible helical spring .22 and perforated disc 23. The coupling 8 has a swivel connection with the nipple 21 andwhen fitted tact with the stem 24 of the valve. The tension. of thes'pring 22 is such-as to overcomethe tension of the spring holding-the valve pressure. to the valve stem 9 holds the valve thereof I unseated.lay-maintaining the disc .23 in eonin presence of two witnesses.

CLARENCE 'i /iiL A nD; i,

Having thus described-the invention, what l clann.1s: e

v 1. An air pump compris ng a cylinder, .a

transverse partitionsub-dividing the cyline der into'two chambers, a piston operable in one of the chambers, means for connecting sive pressure, a valve closing the ventIpassage and operable by excessive pressure-to uncover said vent passage, a springi'or holding said valve normallyseated, and means- "t'or' varying the effective tension. of the spring whereby the pump may .be set for inflatingv tov any; predetermined pounds ,pres} sure. e' f I 2. An air pump comprising a cylinder, a

transverse partition sub-dividing the cylinv der into upper and lowerchambers and havmg a valved passage between the two chambers and a vent passage for the escape of excessive pressure, a valve for closing the" vent passage, a base at the loweryend of the cylinder receiving the lower end of .said

valve, stem, means carried by thevalve stem to be aetedrup'on by excessive pressurelto effect unseating. of theval've at anfopening of the vent passage, a spring :disposed in said base and normally holdingthevalve seated and means adjustable in {the base for regulatingthe effective tension of the spring whereby the pump may be adapted for inflating an article to any required pounds In testimony whereof I afi'ix my signature Witnesses: T. W. HEWITT,

'G. S. MCCLURE. 

